1. Field of the Invention
This invention relates to a surface fastener molded by injection or extrusion and having a substrate sheet and a multiplicity of engaging elements, and more particularly to a molded surface fastener which effectively prevents the substrate sheet from being torn and secures adequate viscosity of a backing glue under various conditions.
2. Description of the Related Art
A surface fastener molded of thermoplastic synthetic resin and having a substrate sheet and a multiplicity of engaging elements standing on a surface of the substrate sheet is already known from U.S. Pat. Nos. 4,725,221, 4,984,339 and 5,131,119.
However, since the substrate sheet of the conventional molded surface fastener has a flat rear surface, a crack would occur in the substrate sheet locally between adjacent rows of engaging elements so that the surface fastener can be easily broken or torn out during sewing.
In the meantime, Japanese Utility Model Publication No. Sho 55-55602 discloses a molded surface fastener in which a woven fiber cloth or a filament film is fused with the substrate sheet, when the substrate sheet is in a melted state, or is attached to the substrate sheet by an adhesive, reinforcing the substrate sheet. But in the surface fastener of such structure, since synthetic resin or adhesive is impregnated into the surface adhering to the woven fiber cloth to make it hard, this reinforced molded surface fastener is not suitable for use in a product that requires adequate softness.